An image processing apparatus such as an MFP (Multi-Function Peripheral) is usually provided with a normal mode in which operating power is fed to each unit and a power saving mode in which the feeding of the operating power to a reading unit configured to read an image, and the like is stopped. For example, when a state in which an operation of each unit is stopped continues for a predetermined time in the normal mode, the image processing apparatus shifts from the normal mode to the power saving mode for saving the power.
There is an image processing apparatus having a USB (Universal Serial Bus) interface, as one of interfaces with an external device. The USB interface enables not only data communication between devices but also power feeding to a power feeding target device such as a smart phone, a tablet and the like. In recent years, the power of maximum 100 W can be fed from the USB interface to the power feeding target device, in accordance with a USB power delivery standard. The image processing apparatus conforming to the USB power delivery USB standard has a PD controller configured to control an amount of power to be fed from the USB interface.
In the normal mode, since the operating power is fed to each unit of the image processing apparatus, when the power feeding target device is connected to the USB interface, the PD controller performs necessary communication with the device connected to the USB interface through a CPU, so that the power is fed to the device. However, when the image processing apparatus is in the power saving mode at the time that the power feeding target device is connected to the USB interface, if the feeding of the operating power to the CPU is stopped, the PD controller cannot perform necessary communication with the device connected to the USB interface and feed the power to the device.